


Accidental Baby Acquisition

by gwendee



Category: Assassination Classroom
Genre: Accidental Baby Acquisition, Alternate Universe, Crack Treated Seriously, Domestic Fluff, Fluff, Gakuren can be read as platonic or romantic, Gen, Humor, I'm confused, If it's romantic then it is, Kid Fic, M/M, Pre-Relationship, please, this is complete nonsense
Language: English
Status: Completed
Published: 2020-12-28
Updated: 2020-12-28
Packaged: 2021-03-10 21:13:34
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,163
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28383783
Author URL: https://archiveofourown.org/users/gwendee/pseuds/gwendee
Summary: Ren gives Gakushuu a phone call. "Um, I think you sent me the wrong list of things to buy, Asano.""No, it's right," Gakushuu says. He sounds even more panicked than before."But, but?!-" Ren's voice drops to a whisper. "-baby stuff? Why do you need diapers-"On Gakushuu's end of the call, the unmistakable wail of an infant rings out.There is a long pause."Okay," Gakushuu starts. "I can explain."
Relationships: Asano Gakushuu/Sakakibara Ren
Comments: 39
Kudos: 158





	Accidental Baby Acquisition

**Author's Note:**

> Hello friends! This fic is nuts.  
> Gakuren nation how are we feeling? I was going to post this yesterday but I exhausted and ended up falling asleep before I wrote the last paragraph. It's here now.

**Ren: not paid enough for this shit**

Ren gets a call from Gakushuu one Sunday Morning. Which is immediately concerning in itself, because Gakushuu never calls people unless in the most dire of consequences. 

Ren picks up the call with trepidation. "Hello?"

"Sakakibara," Gakushuu1 says, and wow, whatever is happening must be bad. This is the most distressed Ren has ever heard Gakushuu say his name - it puts him on high alert. Ren can hear crashing and banging on the other side of the call.

"What's wrong, Asano?" It's 7am and if his ringtone didn't shock him awake, the apparent weight of the situation he still doesn't know about jolts him upright. He gets out of bed.

"I'm going to send you a list of things," Gakushuu says quickly. "I need you to go buy them and head down to my house immediately."

Ren's not awake enough for this. What does Gakushuu need to get at 7 in the morning? "What-"

"Please," Gakushuu says, and that shuts Ren up.

Ren swallows. "Yep. Okay. Be there soon."

Gakushuu sounds relieved. "Thank you. Just… go to a supermarket in a mall. I'll compile the list now. And don't tell anyone about this under _any_ circumstances, okay?"

"Sure-" Ren begins answering, but the call cuts. 

Okay.

Ren gets dressed. 

He's at the supermarket (picking up a couple of snacks and drinks for himself) when Gakushuu's grocery list comes. It must be a long list if he took so long to type it- wait what?

Ren calls Gakushuu.

"Um, I think you sent me the wrong list, Asano," Ren starts.

"No, it's right," Gakushuu says. He sounds even more panicked than before. And… what???

"But, but?!-" Ren's voice drops to a whisper. "-baby stuff? Why do you need diapers-"

On Gakushuu's end of the call, the unmistakable wail of an infant rings out.

There are two long pauses between Ren and Gakushuu. In the background, the baby continues crying.

"Ren, I…" Gakushuu pauses, "I'll explain everything later. Please hurry. Pick up breakfast on the way."

He hangs up again, leaving Ren staring flabbergasted at his phone.

Gakushuu only calls Ren by his first name when he's truly frazzled. A childhood habit that had not been truly beaten out of him by his father.

And also. Gakushuu. Has a baby????

Okay, no, scratch that phrasing. Gakushuu. Has a baby in the house. That he needs to take care of immediately for an unspecified amount of time, given the sheer quantity of baby products he asked Ren to pick up. And this probably came as much of a surprise to Gakushuu as it is to Ren, because of how unprepared he is. 

Okay. That's… okay. Ren doesn't know how he'd feel if his best friend was keeping a whole ass baby from him. 

Ren thinks he'd be better off getting breakfast first before making the baby purchases. He doesn't want to wait in line at the food court with bulk diapers hanging off his arm.

"Asano?" Ren rings the doorbell. There's no answer for a long minute, so Ren begins the tedious process of rearranging his bags so he can figure out which one his phone is in, when the door abruptly opens and a hand yanks him inside.

"Holy f- shit."

It's Gakushuu. And a _baby_.

And okay, all of Ren's previous conclusions fly out the window. Because there is no way this is not Gakushuu's baby. 

Large violet eyes, slightly darker than Gakushuu's blonde hair, and Ren has known Gakushuu since he was seven, okay? He knows what Gakushuuu's baby face looks like. And the resemblance - uncanny. Absolutely identical. Same nose, same round cheeks, same hard-set gaze.

Ren sets the shopping on the floor. "Um-" 

The baby is abruptly thrust into his arms.

"Wh-"

"Hold him, I need to use the bathroom," Gakushuu says quickly. And then he sprints away.

"Wait!" 

Nope. Ren is abandoned with an armful of baby.

Gakushuu's baby.

Gakushuu is a parent. 

Who is- who is the mother? Where is the mother?

Gakushuu… had sex??? 

The baby stares up at him with his father's unmistakable large violet eyes.

"Uh," Ren says. "Hi, little Asano."

The baby bursts into tears. 

"Oh no no no no-"

The baby cries louder.

How do you take care of a baby? Why does Gakushuu have a baby?! GAKUSHUU IS GOING TO KILL HIM FOR NOT BEING ABLE TO TAKE CARE OF HIS BABY?!

"Geez, you're such a drama queen, I was gone for a minute," Gakushuu reappears. He does not kill Ren, and instead takes the baby.

The baby immediately stops crying. He sits happy and pliant in Gakushuu's arms as Gakushuu bounces him.

Gakushuu looks at Ren. "Thank you for coming. You must have questions."

Ren has so many questions. His questions are, who? How? When? Where? Why?!?!

Instead Ren opens his mouth and says, "baby."

Gakushuu grimaces. He looks down at the baby, now sucking his thumb. "It's my father."

"Your… dad had a baby?" That… makes marginally more sense, Ren supposes. So the baby is Gakushuu's brother? Half-brother? Then-

"No," Gakushuu says, wincing again. He takes a deep breath, and Ren braces for impact.

"This baby _is_ my father."

What.

"What," Ren says, out loud. There is nothing to say to that.

And Gakushuu says it with such a deadpan and serious look that Ren almost believes him, except he doesn't, because, what?! 

"What?!" 

"I know, I know!" Gakushuu groans. "Don't… look at me like that!"

"Gakushuu Asano," Ren says, because he feels like his stance needs repeating. So he says, "WHAT?!?!"

"I woke up and my father wasn't home but he had left his phone and all his belongings here, and in his room instead of him there was this… this baby! That looks exactly like him!" Gakushuu says a little hysterically.

And now that Gakushuu mentioned it, the slightly-off shade of hair was identical to Gakuhou's hair color.

But. 

"So that was the first logical conclusion you came up with?" Ren shrieks. "That your father magically _turned into a f- fricking baby?!"_

"When you put it like that…" Gakushuu mumbles, looking away. "This isn't doing much to justify my argument but…" And Gakushuu gazes at the baby with, dare Ren say, the softest look he's ever seen on the boy. "It's like… I just know it's him."

Ren stares. 

Gakushuu lifts the baby and he glares at Ren. "Look at him. He looks like my father."

He looks like _you_ ," Ren says.

"No way," Gakushuu says decisively. "I've never even had… interpersonal relations."

Ren is… he doesn't want to say he's almost sold on the prospect because this situation, no matter how you spin it, is ridiculous. No matter how much the baby looks like Gakuhou or no matter how uncharacteristically affectionate a look Gakushuu gives the baby. Ren has to be the voice of reason. "Isn't it more likely that this is your father's child?"

"I…" Gakushuu makes a face, like he's never considered the possibility. "Why would he leave the baby here?" 

"Maybe he had an angry mother after him and he skipped town," Ren suggests. Which, highly improbable, but still a more rational conclusion than _Gakuhou turned into a baby_ , what the fuck Gakushuu.

Gakushuu looks at the baby.

The baby looks back. Then he gurgles happily, babbles something incoherent at Gakushuu, and lifts his hand to go pat, pat, pat at Gakushuu's cheek.

Ren watches Gakushuu _melt_.

Who knew that their archaic Student Council President's weakness is babies?

"I'm going to go change him into something fitting," Gakushuu says, which is when Ren realizes the baby is dressed in a large T shirt that has been cut and tied in several places. He carries the baby products to the kitchen, and Gakushuu uses the counter as a changing table. Ren averts his eyes for the off chance that the baby is actually somehow Gakuhou, so he heads out to the sitting room to take out the breakfast. He pulls out one of the milk formula packets too.

Gakushuu comes in with the baby in a lion onesie, bouncing on his hip. "Can you hold him? I'll make some milk."

Please don't be Gakuhou, Ren prays. 

He takes the baby.

The baby starts wailing.

Ren passes the baby back to Gakushuu.

The baby settles down.

"I'll mix the milk," Ren says.

"Thank you," Gakushuu says. "He cries every time I put him down. I thought he just wanted to be held, but turns out he wanted to be held by me."

"What are you calling the baby?" Ren says. He doesn't want to keep saying 'the baby'.

"Gakuhou," Gakushuu says.

"Yeah, no."

"You can just call him Asano," Gakushuu says. "It's obvious the baby is related to me one way or another, even if it's my father, my secret brother, or a child I didn't know I had."

All of those were terrible options. He's starting to understand why Gakushuu went with the Gakuhou-turned-into-a-baby route.

It's still more believable to think that Gakuhou accidently knocked someone up, though.

Ren, because he doesn't think he can do any more thinking, heads to the kitchen to follow the milk formula packet's step-by-step instructions. 

He comes back out, warm milk bottle in hand, and steps into the sitting room to see Gakushuu playing with the baby, shaking a little rattle that Ren picked up. The baby laughs, making grabby hands for the toy, as Gakushuu bounces him on a leg.

It's… it's the most adorable thing Ren has ever seen.

He snaps a picture.

"Hey," Gakushuu scolds, but he makes no move to snatch Ren's phone away. Probably because he has a lapful of baby, and also probably because he does want a picture taken. 

Ren hands him the bottle. "It's hot."

Gakushuu hums. 

Ren eats his breakfast silently, watching Gakushuu juggle his own and the milk bottle. The baby coos.

"How old is he?" Ren asks.

"He should be under a year, if we gauge his abilities against normal baby development," Gakushuu says. "He can't walk or talk yet."

"Ah," Ren says. Pause. "What will you do now?"

At that, Gakushuu hesitates. "I don't know," he admits. 

He sounds so confused and defeated that Ren fulfils his duty as best friend to cheer him up. "Come on, you're Gakushuu Asano! You have a plan for everything!"

Gakushuu snorts. "I don't have a contingency plan for accidental baby acquisition, Ren." But then he lapses into a thoughtful silence that can only mean his gears are turning, so Ren silently waits. By this point the baby is bored of nibbling on Gakushuu's thumb and looks around, so Ren picks up the rattle and shakes it.

The baby glares at him.

Maybe not, then.

"I'll have to verify the identity of the baby," Gakushuu decides, "so we'll have to take a DNA test. After which I will make a decision on whether to file a missing person report, hire a private investigator, or find a wizard."

That's as good of a step as any, Ren supposes.

"I really don't think this baby is Gakuhou," he says again.

The baby glares at him, harder. If the baby wasn't Gakuhou, he's doing a really good impression of him.

Gakushuu steamrolls past, ignoring him. "I need to get an at-home DNA test kit, because I doubt I can explain this in a public setting. I'll look for some online."

Ren nods. "Mhm."

"Also, I need your help again to search my house."

"Search… your house."

"For any clues as to what might have transpired," Gakushu clarifies. "I went through the rooms before you arrived, but I think I need a fresh pair of eyes to help discern what's out of place."

"Uh, sure," Ren says.

They proceed to tear apart the house.

Ren more so than Gakushuu, because Gakushuu spends the entire time bouncing a baby on his hip. Because wow, he was not exaggerating at all, and the baby lets out a wail of distress every single time Gakushuu tries to set him down.

Clingy, much?

“I need to use the bathroom again,” Gakushuu says, holding a very petulant baby towards Ren.

“He’s going to scream my ear out,” Ren says.

“I can’t carry him to the bathroom. He cried when I tried to put him in the sink.”

“You tried to put him in the- fine, give me the baby.” 

Ren plugs in his ears.

The baby screams bloody murder.

“You’re such a drama queen!” Gakushuu says, running back from the bathroom. He scoops the baby up in the air and it quietens down, again. Is Ren that hideous? Does he smell bad? Does he have baby repellant on?

“Gakuhou! Don’t be fussy!” Gakushuu says, continuing to baby talk the baby. “Come on, you little rascal. You like Ren!”

Ren’s so taken aback by the sudden revelation - the damn truth bomb Gakushuu suddenly drops - that he doesn’t even comment on the the-baby-is-not-Gakuhou part. “Your dad likes me?”

Gakushuu gives him a deadpan look. “You’ve been my best friend for 7 years. He’s never tried to kill you once. Of course he likes you.”

Ren is… Ren is touched. 

Gakushuu rolls his eyes, like he knows exactly why Ren now has a stupid face on. Can you blame him? Gakuhou’s famous for not liking, well, everyone. Ren feels like he’s passed a hidden monumental test.

Nothing seems out of the ordinary in the house. After hours of searching, the baby even in Gakushuu’s arms becomes fussy, and Gakushuu concludes it is time for lunch.

“So what are you going to do now?” Ren says, when he’s run out for takeout. The baby is asleep now, still in Gakushuu’s arms.

“I’ve ordered a DNA test online,” Gakushuu says. “The kit’s not going to arrive until tomorrow, though.”

Tomorrow. Tomorrow, oh shit.

“Oh shit.”

“What?”

“Asano, tomorrow is Monday.”

The dawning look of horror spreads across Gakushuu’s face. “It’s a school day.” He looks down at the infant. “I’m going to have to call in sick. For both of us.”

Ren buries his face in his hands. “Where did your father go?”

Gakushuu gestures to the baby.

Ren groans. “He’s not the baby, Asano!”

“Yes he is!” Gakushuu insists. 

Ren doesn’t like fighting with Gakushuu, even back when they were kids and Gakushuu was a meeker, more innocent version of himself. He doesn’t like disagreeing with Gakushuu, either, and luckily for him most of their disagreements are settled with compromise (on Ren’s side.)

This, however. Is just going a little bit too far, Ren thinks. 

“Gakushuu,” Ren says seriously. “Look me in the eyes and tell me that you genuinely, one hundred percent, believe that your father magically turned into a baby.”

Gakushuu… looks away. “I… it’s not possible.”

“Yeah, it’s not,” Ren says, relaxing minutely. He’s not sure what he would have to do if Gakushuu continued down this strange path of a delusion-

“But then why would he leave me!” Gakushuu says, suddenly emotional.

Oh shit.

“Um,” Ren panics.

“Why did he leave?!” Gakushuu yells. He jostles the baby awake, who - upon seeing Gakushuu’s distress - decides to start crying as well. 

“He just left me and a baby? A-and, and a baby, he had a whole- he started a family without me? And then what, changed his mind?!”

Ren’s eyes are wide. “Gakushuu-”

“Is it because I got second place at the stupid fucking exams? Is that why he doesn’t want me anymore?”

God: how do you unsend a tweet.

“I’m so, I’m so…” Gakushuu grits his teeth. “I’m so mad at him! If I ever see him again I’m going to break his fucking face in!” He scowls with resolve.

Ren doesn't know if he's terrified or proud.

And then his demeanor abruptly switches, and he’s rocking the baby in his arms again. “Sorry sweetie, don’t cry, I wasn’t mad at you…”

“72 hours,” Gakushuu decides. “72 hours and if he doesn’t turn up, I’m filing a missing person report.”

“What about the DNA test?” Ren asks.

Gakushuu shrugs. “I’ll still take it, since it’s already on its way. Then maybe I’ll get an official one, to help with custody issues.”

Gakushuu’s been chillingly stoic since his outburst in the afternoon. Ren is worried.

“Hey,” Ren starts. “About your father.”

“I don’t want to talk about him,” Gakushuu says stubbornly. 

Ren sighs. “Alright. Then… about tomorrow… you can call in sick. But what happens after that? Are you going to… raise the kid?”

“I…” Gakushuu bites his lip. “Ren, I don’t know wh-what to do.”

“Gakushuu…”

And then Gakushuu startles him by hugging him. The baby makes a noise of protest at being squished between them, and it’s not really one of those big long hugs because of the obstruction, but it’s a hug nonetheless. 

Ren quickly wraps his arms around Gakushuu’s shoulder.

They have not hugged since they were ten.

“I don’t know what I’ll do without you,” Gakushuu admits.

Ren, despite himself, feels heat surge up to his cheeks. 

Before he manages a reply, Gakushuu says, “thank you for being here,” which just decimates Ren on the spot, really.

And then the baby decides he’s had enough of being sandwiched and slaps Ren in the face with his little hands, as if this whole debacle was Ren’s idea.

“Alright, alright,” Gakushuu says, placating the baby, turning away from Ren. Ren didn’t know that an infant could radiate so much _smugness_ in a single look, but boy.

Ren glares at him.

The baby glares back.

“I’m pretty sure infants are supposed to sleep more,” Gakushuu says. “This baby’s been awake since 7 in the morning.”

“He took a nap just now after lunch,” Ren says.

Gakushuu looks uncertain. “Still. Should I bring him to a doctor?”

“It might be a good idea,” Ren says. “To get more professional advice on, um, baby caring.”

The baby babbles. Gakushuu hikes it higher up his side. 

“How did you find the baby?” Ren asks.

“My father was missing from the house,” Gakushuu says. “I thought he might have had errands to run, but when I passed by his room I heard, well, crying. I went in and there was this baby on his bed, rolling about in his blankets and clothes...” Gakushuu pauses. “He left his phone on the bedside table, and he didn’t move anything, really. He normally takes a morning jog, and I know he went on one this morning because his bathroom floor was still wet, which means he came home and took a shower after.”

“Mhm,” Ren says. “Or he went out and got the baby.”

Gakushuu makes a face, but nods. “There wasn’t a single thing in the house suited for an infant! So I called you. It was dangerous, you know,” he says. “I hear that infants die because they get trapped in blankets and pillows, and suffocate to death. Father really is irresponsible, doing what he did…”

A thought occurs to Ren. “Do you have a crib for the baby?”

Gakushuu frowns. “No. I was thinking of just sleeping with him for now. My bed’s big enough, and I’m a light sleeper…”

Ren frowns. “I could go buy one now.”

Gakushuu shakes his head. “It’d be too big for you to drag back alone. That’s okay, I think you’ve helped me plenty today. I’ll pay you back for all the stuff you bought.”

Ren shakes his head. “It’s fine. What do you want for dinner? I’ll go get takeout again.”

“Oh!” Gakushuu tilts his head. “You don’t have to. I can just order in.”

“It’s fine,” Ren says. “What if you need to use the bathroom at night? Don’t leave your baby in the sink.”

Gakushuu rolls his eyes, but he’s smiling. “I’ll need to start teaching the baby to be less attached to me.”

“Well, you’re the better Asano,” Ren jokes. Then, “I can stay the night. In case anything happens or if the baby is fussy… we can take turns.”

Gakushuu looks at him, an unreadable expression on his face, and Ren immediately wants to backpedal.

“If you don’t mind,” he adds on.

“I don’t,” Gakushuu says. “Thank you.”

And then Gakushuu smiles at him, the setting sun illuminating his face in the window, and not for the first time, Ren is reminded of how pretty his best friend is.

The baby in his arms makes the scene… all the more cute.

Cute.

They have not had a sleepover in Gakushuu’s house in… well, ever, Ren thinks. Ren was too terrified of Gakuhou to ever want to sleep over. Gakushuu stayed over at his house sometimes.

“I set up a guest room for you,” Gakushuu says. He’s still holding the baby.

“Doesn’t your arm get tired?” Ren says.

“Hm? A little.” Gakushuu moves the kid to the other arm. “It’s like holding a watermelon that cries.”

The watermelon in question squeals, and tugs hard on the towel slung around Gakushuu’s neck. 

Gakushuu gave the baby a bath, and Ren was somehow delegated to standby, which ended up being an important job because Gakushuu emerged sopping wet and said with finality that the next baths have to be taken together to kill two birds with one stone. And then he pawned the baby off to Ren, both of whom were less than pleased, and went back to finish his shower. Which, speaking of, is such a strange domestic thing that gives Ren an odd feeling in his chest.

“Remember if anything happens, you can just wake me up,” Ren says. “I don’t care how late at night it is, okay?”

“Sure, sure,” Gakushuu says.

Ren wakes up with his full 8 hours of sleep the following morning and thinks, Gakushuu is either a liar, or this is the best behaved baby he’s ever seen.

“Gakushuu? You okay?” Ren yawns, trodding down the hallway to Gakushuu’s room. Gakushuu’s an earlier riser than him, Ren always receiving texts even before he wakes up. Maybe he’s super worn out about the baby. Ren should have left his room door open so he can hear some noise, it’s just like Gakushuu to think he can handle everything and pass out afterwards. 

He considers knocking, but then he decides that if the baby or Gakushuu were still asleep, he would wake them up. 

Just a little peek, Ren says, to check that they’re alright. Then he’ll get started on breakfast.

Wouldn’t it be insane if Ren opened the door and Gakushuu was now a baby? Because that would mean that that was really Gakuhou as a baby. Which would mean that this house is haunted, and then Ren is next.

Ren opens the door.

“What.”

“Sakakibara,” Gakuhou, all adult and grown up and staring sheepishly at Ren, is squished into Gakushuu’s bed. Gakushuu has his arms wrapped around Gakuhou, and he’s still snoozing quietly.

Ren looks left, right, up, down. There’s no baby.

Ren makes direct eye contact with Gakuhou.

This is the most he’s seen of Gakuhou being flustered. He has a blush on his face, and he’s awkwardly patting Gakushuu’s head.

“Was that…” Ren tries to whisper, but he thinks he’s a little bit too dumbfounded to whisper. “You, yesterday. You were…”

Gakuhou stares silently at him, face still red. Very slowly, he nods.

Gakushuu shifts in his sleep.

Ren watches in abject horror as Gakuhou looks down at his son with the fondest look in the world, and then looks back up at Ren with a death stare.

This is it. Ren, as the sole witness to the emotional vulnerability displayed today, will die.

Then Gakuhou rolls his eyes and leans back against the headboard.

Wait. What had Gakushuu said? That Gakuhou actually liked him? God is real and shining down on Ren.

And also.

"You turned into a baby?!" Ren shout-whispered, and Gakuhou looks pained.

Okay. This is.

"How."

Gakuhou shrugs. “I don’t know.”

Ren stares at him. “Do you… remember… what happened yesterday? When you were…”

Gakuhou nods.

Oh dear god.

Ren doesn’t know if he believes in any of this. He doesn’t know if he’s still halfway in a fever dream, or if he’s somehow isekai-ed into a magical world where nothing makes sense. What he does know is this: Gakuhou’s back, so Gakushuu will deal with it.

"I can't deal with this," Ren says. 

Gakuhou nods as if to say, that's fair.

"I'm going downstairs to make breakfast," Ren says. 

Ren is peacefully flipping his omelets when he hears a bloodcurdling scream from upstairs. 

"YOU!"

Ren adds some salt to the egg.

"WHERE THE FUCK IS MY BABY?!" 

He hums, and adds some pepper.

"I'M GOING TO KILL YOU!"

Ah. It’s good to see everything is back to normal.

**Gakushuu? Having baby fever? It's more likely than you think.  
**

**Free PC check now**

**Please don't ask me how any of this happened because I don't know either**

**It will be a mystery forever**

**Who needs to know, really?**

**Author's Note:**

> I'm sorry for writing this  
> Thanks for reading, hope you liked it!


End file.
